In recent years, many semiconductor devices have been produced by the mounting method known as the face-down method. In this method, during mounting of a semiconductor chip having a circuit surface on which electrodes such as bumps or the like have been formed, the circuit surface side of the semiconductor chip is affixed to a chip-mounting unit such as a lead frame. Accordingly, a structure is formed in which the back surface of the semiconductor ship on which no circuit is formed is exposed.
As a result, in order to protect the semiconductor chip, a protection membrane formed from a hard organic material is often formed on the back surface of the semiconductor chip. This protection membrane is formed, for example, using the type of semiconductor back surface film or dicing tape-integrated wafer back surface protection membrane described in Patent Document 1.
In some cases, the protection membrane may also be used as a member for displaying information relating to the workpiece (for example, a semiconductor wafer) or processed product (for example, a semiconductor chip) on which the protection membrane is provided. In other words, in some cases a printing process is performed in which information relating to the workpiece or the processed product is displayed in a visible manner by forming unevenness on the surface of the protection membrane. This printing process is typically performed by irradiating a laser onto the surface of the protection membrane.
In this regard, the semiconductor back surface film disclosed in Patent Document 1 exhibits a light transmittance of 20% or less at a wavelength of 532 nm or 1,064 nm. This enables a printing process to be performed by laser beam irradiation, while preventing any adverse effects on the semiconductor element caused by the laser beam.